U.S. patent application number 12/425627 was filed with the patent office on 2009-09-24 for soft tissue defect repair device.
Invention is credited to Jerald M. Crawley, John M. Herman, William D. Montgomery, Charles F. White.
Application Number | 20090240267 12/425627 |
Document ID | / |
Family ID | 33517434 |
Filed Date | 2009-09-24 |
United States Patent
Application |
20090240267 |
Kind Code |
A1 |
Crawley; Jerald M. ; et
al. |
September 24, 2009 |
Soft Tissue Defect Repair Device
Abstract
An inguinal hernia repair device in the form of an implantable
plug that is affixed at one end to the center region of a sheet of
implantable material. The plug takes the form of a plurality of
hollow members, arranged so as to be in substantially parallel
relationship when implanted into a defect. The hollow members are
preferably tubular members and are preferably bundled together by
various means, such as bonding or wrapping a band or strand about
the plurality of hollow members to maintain them in adjacent and
contacting relationship during insertion into a defect. The device
is provided with a base member for anchorage made of a composite
material having a non-bioabsorable component and a bioabsorbable
component.
Inventors: |
Crawley; Jerald M.;
(Flagstaff, AZ) ; Herman; John M.; (Elkton,
MD) ; Montgomery; William D.; (Flagstaff, AZ)
; White; Charles F.; (Camp Verde, AZ) |
Correspondence
Address: |
Eric J. Sheets;W. L. Gore & Associates, Inc.
551 paper Mill Road, P.O. Box 9206
Newark
DE
19714-9206
US
|
Family ID: |
33517434 |
Appl. No.: |
12/425627 |
Filed: |
April 17, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11015147 |
Dec 17, 2004 |
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12425627 |
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10465110 |
Jun 18, 2003 |
6991637 |
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11015147 |
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Current U.S.
Class: |
606/151 ;
623/11.11 |
Current CPC
Class: |
A61F 2/0063 20130101;
A61B 17/0057 20130101; A61B 2017/00615 20130101; A61B 2017/00597
20130101 |
Class at
Publication: |
606/151 ;
623/11.11 |
International
Class: |
A61B 17/08 20060101
A61B017/08 |
Claims
1. An implantable device comprising a plurality of substantially
hollow members; wherein each said substantially hollow member has a
length and a midpoint along said length; wherein each substantially
hollow member has two ends and at least one of said ends is open;
and wherein each substantially hollow member is attached to a
substantially planar base member at about said midpoint of said
substantially hollow member.
2. The implantable device of claim 1 comprising a bioabsorbable
material.
3. The implantable device of claim 2 wherein said bioabsorbable
material comprises polyglycolic acid.
4. The implantable device of claim 3 wherein said bioabsorbable
material comprises trimethylene carbonate.
5. The implantable device of claim 1 comprising a non-bioabsorbable
material.
6. The implantable device of claim 5 wherein said non-bioabsorbable
material comprises polytetrafluoroethylene.
7. The implantable device of claim 1 comprising a bioabsorbable
material and a non-bioabsorbable material.
8. The implantable device of claim 7 wherein said bioabsorbable
material comprises polyglycolic acid
9. The implantable device of claim 8 wherein said bioabsorbable
material comprises trimethylene carbonate.
10. The implantable device of claim 7 wherein said bioabsorbable
material comprises trimethylene carbonate.
11. The implantable device of claim 7 wherein said
non-bioabsorbable material comprises polytetrafluoroethylene.
12. The implantable device of claim 8 wherein said
non-bioabsorbable material comprises polytetrafluoroethylene.
13. The implantable device of claim 9 wherein said
non-bioabsorbable material comprises polytetrafluoroethylene.
14. The implantable device of claim 10 wherein said
non-bioabsorbable material comprises polytetrafluoroethylene.
15. The implantable device of claim 1 wherein said substantially
hollow members comprise a bioabsorbable material.
16. The implantable device of claim 15 wherein said bioabsorbable
material comprises polyglycolic acid
17. The implantable device of claim 16 wherein said bioabsorbable
material comprises trimethylene carbonate.
18. The implantable device of claim 15 wherein said bioabsorbable
material comprises trimethylene carbonate.
19. The implantable device of claim 15 wherein said substantially
planar base member comprises a non-bioabsorbable material.
20. The implantable device of claim 19 wherein said
non-bioabsorbable material comprises polytetrafluoroethylene.
21. The implantable device of claim 16 wherein said substantially
planar base member comprises a non-bioabsorbable material.
22. The implantable device of claim 21 wherein said
non-bioabsorbable material comprises polytetrafluoroethylene.
23. The implantable device of claim 17 wherein said substantially
planar base member comprises a non-bioabsorbable material.
24. The implantable device of claim 23 wherein said
non-bioabsorbable material comprises polytetrafluoroethylene.
25. The implantable device of claim 18 wherein said substantially
planar base member comprises a non-bioabsorbable material.
26. The implantable device of claim 25 wherein said
non-bioabsorbable material comprises polytetrafluoroethylene.
27. The implantable device of claim 1 wherein said substantially
planar base member comprises a non-bioabsorbable material.
28. The implantable device of claim 27 wherein said
non-bioabsorbable material comprises polytetrafluoroethylene.
29. The implantable device of claim 27 wherein said substantially
planar base member further comprises a bioabsorbable material.
30. The implantable device of claim 28 wherein said substantially
planar base member further comprises a bioabsorbable material.
31. The implantable device of claim 28 wherein said bioabsorbable
material comprises polyglycolic acid.
32. The implantable device of claim 29 wherein said bioabsorbable
material comprises trimethylene carbonate.
33. The implantable device of claim 29 wherein said bioabsorbable
material comprises polyglycolic acid.
34. The implantable device of claim 1 wherein the implantable
device is a hernia repair device.
35. The implantable device of claim 1 wherein the implantable
device is a soft tissue repair device.
36. An implantable device comprising at least one substantially
hollow member; wherein said at least one substantially hollow
member has a length and a midpoint along said length; wherein each
substantially hollow member has two ends and at least one of said
ends is open; and wherein each substantially hollow member is
attached to a substantially planar base.
37. The implantable device of claim 36 wherein the substantially
hollow member is attached to the substantially planar base at about
said midpoint of said substantially hollow member.
38. The implantable device of claim 1 wherein the substantially
hollow member is conformable to the shape of a defect.
39. The implantable device of claim 1 wherein the plurality of
hollow members are compressible.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of application Ser. No.
11/015,147, filed Dec. 17, 2004, which is a continuation-in-part of
application Ser. No. 10/465,110, filed Jun. 18, 2003, and now
issued as U.S. Pat. No. 6,991,637.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of soft tissue
defect repair devices, and more particularly to the field of
inguinal hernia repair devices.
BACKGROUND OF THE INVENTION
[0003] The repair of inguinal hernias is one of the most commonly
performed surgical procedures. Various prosthetic materials,
typically porous to allow for tissue ingrowth, have been provided
in a variety of combinations, forms and shapes. Surgical mesh,
typically of polypropylene, has been commonly used, in some
instances having been rolled up into a cylindrical shape and
inserted into the defect as a plug. To reduce the tendency to
migrate, these plugs are sometimes affixed at one end to the center
of a sheet of material. The sheet is used to overlap the defect and
for attachment to the adjacent tissue to reduce the likelihood of
migration of the device; see, for example, U.S. Pat. No. 5,116,357
to Eberbach and U.S. Pat. No. 5,147,374 to Fernandez. These
sheet-and-plug devices lend themselves to laparoscopic repair as
they may be inserted via a trocar wherein, after insertion, the
edges of the sheet may be fastened to the tissue adjacent the
defect.
[0004] Hernia repair plug devices have been refined into a variety
of shapes. One such commercially available device is the
PerFix.RTM. Plug from C.R. Bard, Inc. (Murray Hill N.J.), described
in U.S. Pat. No. 5,356,432 to Rutkow et al. and in revised form by
U.S. Pat. No. 5,716,408 to Eldridge et al. This device is in the
form of a pleated conical fabric mesh provided with additional mesh
filler material within the hollow of the cone; a sheet of material
is not attached to the plug. These attributes are said to aid in
the insertion of the device into a hernia defect (In the axial
direction with regard to the device) and to better enable the
device to fill the defect in the radial direction. However, there
are reported cases of devices of this type having migrated from the
site of the defect. Further, the mesh filler material is often not
adequate to provide the necessary axial stiffness and radial
compliance to the conical form.
[0005] U.S. Pat. No. 6,425,924 to Rousseau teaches two opposing
conical mesh shapes fitted together on a common axis and separated
by one or more tubular components, also on the common axis, with
the apices of the two cones pointed away from each other. The apex
of one cone is affixed to the center of a sheet of mesh
material.
[0006] Various materials have been discussed for use as prosthetic
plugs for the repair of inguinal hernias. Polypropylene and
polytetrafluoroethylene are commonly discussed. Polypropylene is
most often used in the form of a woven or knitted mesh fabric to
create the desired shapes. Polytetrafluoroethylene is typically
used in its porous, expanded form, usually noted as ePTFE. Other
described non-absorbable materials include cotton, linen, silk,
polyamide (e.g., nylon 66) and polyethylene terephthalate. Various
absorbable materials have also been proposed, including
homopolymers and copolymers of glycolide and lactide, caprolactones
and trimethylene carbonates. See, for example, U.S. Pat. No.
6,113,641 to Leroy et al., U.S. Pat. No. 6,180,848 to Flament et
al., and U.S. Pat. No. 6,241,768 to Agarwhal et al.
[0007] U.S. Provisional Patent Application Ser. No. 60/405,517 to
Gingras discloses a soft tissue implant used to treat body defects
or to remodel tissue. The implant is in the form of a braided or
woven material having a variety of shapes. The braided or woven
material can be made of non-absorbable or absorbable polymeric
material. The Gingras device does not combine absorbable materials
with non-absorbable materials, however. An onlay or anchor can be
attached to the implant to reduce or eliminate migration of the
implant.
[0008] An implantable space-filling tissue repair device having an
anchoring element made of non-bioabsorbable components in
combination with bioabsorbable components would provide different
tissue responses to the anchoring element at different times during
the healing and/or remodeling process. In addition, the
bioabsorbable materials of the anchoring element would alter the
mechanical characteristics of the non-bioabsorbable materials of
the element. This would allow for more variability in the design
and construction of the non-bioabsorbable materials of the
anchoring element. Once the bioabsorbable material has disappeared
from the anchoring element, the non-bioabsorbable component would
remain in place and continue to provide support to the repaired or
remodeled tissue.
[0009] Accordingly, there remains a need for an implantable medical
device having a bioabsorbable and/or non-bioabsorbable
space-filling portion and one or more anchoring elements made of
non-bioabsorbable materials in combination with bioabsorbable
materials. A preferred bioabsorbable material would be a synthetic
polymeric material in the form of a self-cohering web.
SUMMARY OF THE INVENTION
[0010] The present invention is directed to an inguinal hernia
repair device in the form of an implantable plug that is affixed at
one end to the center region of a sheet of implantable material,
with the length of the plug component oriented to be substantially
perpendicular to the sheet. The implantable sheet material is
substantially planar and serves as a base member for the
implantable plug portion of the present invention to participate in
anchoring the invention at an implantation site. Accordingly, the
implantable sheet material is referred to herein either as an
"anchoring element," or a "base member."
[0011] In this invention, the base member is made of one or more
non-bioabsorbable components in combination with one or more
bioabsorbable components. The non-bioabsorbable component is
preferably polymeric. Suitable non-bioabsorbable polymeric
materials include biocompatible alkenes, such as polyethylene and
polypropylene, and biocompatible fluoropolymers. Preferred
non-bioabsorbable polymeric materials are configured with a
multiplicity of pores, voids, holes, or other spaces through and/or
throughout the material. The spaces can be of various sizes and are
either isolated or interconnected in the polymeric material. In
preferred embodiments, these spaces in the non-bioabsorbable
component serve as repositories for the bioabsorbable component. In
many preferred embodiments, the bioabsorbable component is
selectively placed within spaces and/or on surfaces of the
non-bioabsorbable component. Selectively placing the bioabsorbable
component on the non-bioabsorbable component permits the tissue
response and the mechanical properties of the base member to be
altered, or adjusted, for a particular medical procedure or
physiological requirement.
[0012] The plug portion of the present invention takes the form of
a plurality of hollow, or substantially hollow, members, arranged
so as to be in substantially parallel relationship when implanted
into a defect. The hollow members are preferably bundled together
by various means, such as bonding or wrapping a band or strand
about the plurality of hollow members to maintain them in adjacent
and contacting relationship during insertion into a defect.
[0013] The hollow members are preferably tubular in shape and can
be made of non-bioabsorbable materials and/or bioabsorbable
materials. Preferably, the hollow members are made of a non-woven
bioabsorbable material. More preferably, the non-woven
bioabsorbable material is in the form of a web. Most preferably,
the non-woven bioabsorbable web is a self-cohering web. The use of
a plurality of hollow members provides for good axial stiffness,
beneficial during insertion into the defect, in combination with
good radial compliance due to the transverse compressibility of the
relatively thin-walled tubes. Preferably, a plurality of discrete,
individual hollow members are used, with at least one end of each
hollow member remaining open to allow rapid access for body fluids
and living cells. The open end of the hollow members is located at
the end of the plug opposite the end that is affixed to the sheet
of implantable material. As noted above, the plurality of hollow
members may be affixed at one end to the center region of a sheet
of implantable material that serves to anchor the device in the
preperitoneal space and ensure proper placement and retention of
the plug.
[0014] In a preferred embodiment, the hollow members are about
twice the desired length of the plug component. Each hollow member
is folded in half at the midpoint of its length, with all hollow
members attached at the fold to the sheet component. The plurality
of folded hollow members is then bundled together as described
above.
[0015] The hollow members and the sheet component may be made from
any suitable implantable materials including both bioabsorbable and
non-bioabsorbable materials. The entire device may be made to be
non-bioabsorbable, or alternatively the entire device may be made
to be absorbable. The plug may be made to be absorbable and affixed
to a non-bioabsorbable sheet, or vice versa. Bioabsorbable
materials are preferred, particularly for the plug component, in
that they are anticipated to elicit an inflammatory tissue response
that may result in more rapid healing. The most preferred sheet
materials have one or more non-bioabsorbable components placed
within, or between, bioabsorbable components.
[0016] If desired, the length of the substantially hollow members
may be reduced by trimming with a cutting tool.
[0017] A preferred bioabsorbable material for the hollow member
components and the bioabsorbable components of the base member
material is a copolymer of poly(glycolide:trimethylene carbonate).
The copolymer's polyglycolide component is commonly abbreviated as
PGA for poly(glycolic acid), the chemical byproduct to which it
degrades after hydrolysis. The poly(trimethylene carbonate)
component is commonly abbreviated as TMC, with the copolymer itself
typically referred to as PGA:TMC accompanied with relative
percentage composition by weight. The preferred PGA:TMC copolymer
embodiment is in the form of a non-woven self-cohering web as
taught by Hayes in U.S. Pat. Nos. 6,165,217 and 6,309,423, both of
which are incorporated herein by reference.
[0018] Preferably, the non-bioabsorbable component is made of a
fluoropolymer. More preferably, the fluoropolymer is
polytetrafluoroethylene. Most preferably, the
polytetrafluoroethylene is porous, expanded,
polytetrafluoroethylene (ePTFE). Other polymeric materials suitable
for use in making non-bioabsorbable portions of the device include,
but are not limited to, polyethylene and polypropylene Either or
both of the sheet component and the space-filling plug component
may optionally be treated (e.g., impregnated or coated) with any of
various bioactive agents, including but not limited to
antimicrobials, antibiotics, palliatives, and pharmacological,
biochemical, and genetic therapeutics. This is possible regardless
of whether the material used for the treated component is
bioabsorbable or non-bioabsorbable.
[0019] Accordingly, one embodiment of the present invention is an
implantable hernia repair device comprising a plurality of
substantially hollow members, wherein each substantially hollow
member has two ends and at least one of said ends is open, wherein
each substantially hollow member is made of a bioabsorbable
polymeric material in the form of a self-cohering web, and wherein
said plurality of substantially hollow members is attached to a
substantially planar base member in the form of a composite made of
a non-bioabsorbable polymeric material placed within a
bioabsorbable polymeric material in the form of a self-cohering
web.
[0020] Another embodiment of the present invention is an
implantable hernia repair device comprising a plurality of
substantially hollow members, wherein each substantially hollow
member has two ends and at least one of said ends is open, wherein
each substantially hollow member is made of a bioabsorbable
polymeric material in the form of a self-cohering web, and wherein
said plurality of substantially hollow members is attached to a
substantially planar base member in the form of a composite made of
a non-bioabsorbable polymeric material placed between at least two
layers of a bioabsorbable polymeric material in the form of a
self-cohering web.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a perspective view of a hernia repair device of
the present invention.
[0022] FIG. 1A is a side view of a method of making the device of
FIG. 1.
[0023] FIGS. 1B and 1C are top views further illustrating the
method of FIG. 1A.
[0024] FIG. 2 is a perspective view of an alternative hernia repair
device of the present invention wherein a corrugated sheet is
rolled to create the plug component.
[0025] FIGS. 2A and 2B are upper and lower perspective views of the
corrugated sheet prior to rolling up to create the plug.
[0026] FIG. 3 is an end view of an embodiment wherein the hollow
members have hexagonal transverse cross sections.
[0027] FIG. 4 is a perspective view of a hernia plug incorporating
a barb component around the circumference of the plug.
[0028] FIG. 5 is a perspective view of an embodiment of the hernia
repair device incorporating a layered sheet component
[0029] FIG. 5A shows a cross-section of a composite sheet material
for use with the hernia repair device.
[0030] FIG. 5B shows a cross-section of a composite sheet material
for use with the hernia repair device.
[0031] FIG. 5C shows a cross-section of a composite sheet material
for use with the hernia repair device.
[0032] FIG. 6 is a longitudinal cross section that describes an
alternative way to accomplish the attachment of the plurality of
hollow members to the sheet component.
DETAILED DESCRIPTION OF THE INVENTION
[0033] FIG. 1 is a perspective view of a hernia repair device 10 of
the present invention, wherein a plurality of hollow, or
substantially hollow, members 12 are provided in substantially
parallel relationship, creating plug 14. Preferably, hollow members
12 are tubular as shown in this embodiment. Optionally and
preferably, one end of plug 14 is affixed to the approximate center
of a sheet 16 of composite implantable material. Sheet 16 may
optionally be provided with one or more slits 17 as desired to
increase flexibility of sheet 16 and to better enable it to be
folded as necessary for insertion.
[0034] Though preferred, hollow members 12 are not required to be
tubular. Consequently, each hollow member 12 is not required to
have either a round or continuous (uninterrupted) circumference.
The hollow members may, for example, be tubes provided with a slit
along all or a portion of their length in order to further increase
their radial or transverse compressibility. While round transverse
cross sections are preferred, other shapes such as square,
rectangular, hexagonal, elliptical, etc. may be used. The
transverse cross sectional shapes of the hollow members making up
an individual plug may all be the same, or two or more different
transverse cross sectional shapes may be used in combination to
make up a single plug.
[0035] Hollow members 12 are preferably provided in a bundle that
results in their being substantially parallel to each other when
inserted. By "substantially parallel" in this context is meant that
the hollow members vary only about +/-20 degrees, and more
preferably only about +/-10 degrees, from perfectly parallel. The
hollow members may be maintained in a bundled relationship by
various bundling means, such as bonding together outer surfaces of
adjacent hollow members or wrapping a band 18 or strand about the
plurality of hollow members 12 to maintain them in adjacent and
contacting relationship during insertion into a defect. The bundled
relationship may also result from the means used to affix the
individual hollow members 12 to a sheet 16.
[0036] For embodiments wherein plug 14 is fabricated from a
bioabsorbable material, band 18 or any other suitable bundling
means may be made from an a material that bioabsorbs, bioresorbs,
or dissolves faster than the material of plug 14. As such, band 18
(or other bundling means) can be expected to bioabsorb, bioresorb,
or dissolve before the plug and will release the hollow members to
allow them to better conform to the shape of the defect into which
they were inserted when contained by the bundling means.
[0037] Hollow, or substantially hollow, members 12 have opposing
ends wherein one end of each of the plurality of hollow members
remains open, thereby allowing access of body fluids and cells into
the luminal space of each hollow member. This is anticipated to
increase the rate of tissue attachment and healing, particularly if
the hollow members 12 comprise a bioabsorbable material. The end of
each hollow member 12 opposing the open end may be affixed to the
central region of sheet 16.
[0038] Alternatively, as shown by FIG. 1A, each hollow member 12
may be of a length that is about twice the length of plug 14,
wherein individual hollow members 12 are folded in half
transversely (indicated by arrows 22) at about the midpoint of
their length, and attached at the fold to sheet 16.
[0039] Attachment of hollow members 12 to sheet 16 may be
accomplished in a variety of manners, depending on the
configuration of hollow members 12 and the materials selected for
the hollow members 12 and sheet 16. The various affixing means
include the use of adhesives suitable for the chosen materials,
various mechanical attachment means such as sewing with suitable
materials (e.g., suture materials), or welding means such as the
appropriate application of heat, solvent welding and/or by
ultrasonic welding.
[0040] A preferred method of making the embodiment with folded
hollow members is shown in the top views of FIGS. 1B and 1C. FIG.
1B shows how a hollow member 12 may be provided with opposing
notches 24 along its sides to better enable additional hollow
members to be stacked at the same attachment point as further shown
in FIG. 1C. Notches 24 reduce the interference resulting from
multiple hollow members 12 being attached at different angles at
the common location. It is apparent that a plurality of hollow
members 12 may be attached at the common location in this manner.
The hollow members may be further provided with a hole 26 at the
center of the transverse fold line to accommodate a temporary
locating pin (not shown for clarity; for use only during
fabrication until the assembly is complete). Conversely, such a
locating pin might be made from a suitable bioabsorbable material
and remain in place as a part of the device construction.
[0041] FIG. 2 is a perspective view of an alternative hernia repair
plug of the present invention describing an embodiment wherein the
hollow members 12 are in the form of a corrugated material 32 that
is rolled up or otherwise bundled to form plug 14. The corrugated
material 32 may be rolled up to create the plug 14 or simply folded
and bundled by wrapping with a band 18 or my other means described
previously. Plug 14 is affixed to sheet 16 as described previously.
For any of the embodiments described herein, the resulting juncture
of plug 14 and sheet 16 may be optionally reinforced by a fillet
component 39. Fillet 39 is simply a disc of suitable material
fitted around the base of plug 14 with enough interference to cause
it to fit tightly around the base of plug 14. Fillet 39 may be
joined to sheet 16 and plug 14 by various affixing methods
described previously. Alternatively, sheet 16, fillet 39 and band
18 may be formed of a single piece.
[0042] FIGS. 2A and 2B show respectively upper and lower
perspective views of a corrugated sheet material suitable for
rolling or otherwise bundling to create plug 14. The corrugated
sheet 32 comprises an upper layer 34 that is corrugated and affixed
to a planar lower layer 36 by any suitable means. The corrugations
result in a plurality of hollow members 12. Rolling of the
corrugated sheet 32 to create plug component 14 is accomplished by
rolling in a direction transverse to the length of the
corrugations. As shown by FIG. 2, this results in the corrugations
that provide the plurality of hollow members 12 extending along the
length of the cylindrical plug 14, parallel to the longitudinal
center line of the plug 14. The ends of the corrugations, opposite
the end of the plug that is subsequently affixed to sheet 16,
remain open. The corrugated sheet material 32 may be made from any
desired bioabsorbable or non-bioabsorbable material. These
corrugated sheets are anticipated to have other implantable
applications in addition to use as the plug component of the hernia
repair device described herein. For example, the corrugated sheet
material 32 may be useful in planar form for the repair of various
tissue defects where a somewhat flexible, but "reinforced" sheet is
desired. They may also have utility when rolled up to create a
cylindrical shape appropriate for other applications. The hollow
members resulting from the corrugated construction may be
beneficial for various implantable applications.
[0043] Optionally, as shown by FIGS. 2A and 2B, corrugated sheet
material 32 may be provided with one or more transverse
corrugations 38 on the lower surface of planar lower layer 36. When
the corrugated sheet material is rolled up to create plug 14 of
FIG. 2, these corrugations 38 become barbs or anchoring features
extending circumferentially around the outer surface of plug 14, as
will be further described. Corrugations 38 must be adequately
flexible or distortable to allow the corrugated sheet 32 to be
rolled up in the direction of their length. If desired,
corrugations 38 may be cut transversely at intervals along their
length to better enable the corrugated sheet 32 to be rolled up
FIG. 3 shows a top view of plug 14 wherein the hollow members 12
have hexagonal transverse cross sections. Plug 14 may result from
bundling a plurality of individual hollow members 12 or
alternatively the members may be provided by extrusion of a
honeycomb form wherein adjacent hollow members 12 share common
walls. It is apparent that hollow members 12 may be provided in a
variety of cross sectional shapes.
[0044] FIG. 4 shows a perspective view of a plug 14 provided with a
band 18 that includes one or more barbs 42, intended to aid in the
securement or anchoring of plug 14 within a tissue defect.
Additionally, barbs 42 may serve as the band component 18 that
holds hollow members 12 together in a bundle. These barb components
42 may be made in a variety of ways. FIG. 4 shows two barbs made
from discs of bioabsorbable material and provided with flanges 44
that enable the attachment of barbs 42 to the outer surface of plug
14. These anchoring barbs 42 may also be made by providing
transverse corrugations 38 to corrugated sheet 32 prior to rolling
corrugated sheet 32 to form plug 14, as described previously and
shown in FIGS. 2A and 2B.
[0045] The preferred bioabsorbable material for making the present
invention is in the form of a web of continuous filaments which are
made of at least one semi-crystalline polymeric component
covalently bonded as a linear block copolymer with or blended with
one or more semi-crystalline or amorphous polymeric components. The
filaments are intermingled together to form a porous web of
filaments, the filaments having multiple contact points with each
other within the web. The filaments are bonded at the contact
points without requisite for added adhesive binders, adjuncts or
post extrusion melt processing. The web may be provided in forms
with relatively high cohesive shear strength. The polymeric
components of the filaments exist, at least temporarily, in a
homogenous substantially phase miscible uncrystallized state. If
preserved in the homogenous substantially phase miscible
uncrystallized state, the object can then be manipulated into a
distinct desirable molded shape and then subsequently set or
crystallized to retain the desired form particularly suitable for a
specific use or application. Such a web is referred to herein as a
"self-cohering," "self-bonding," or "autogenous-bonding" web.
Accordingly, a self-cohering web has the ability of a melt formed
structure, or component thereof, to effectively self-generate an
attachment to itself without the requirement to undergo a melt, or
undergo the requisite addition of supplementary adhesives, binders,
or adhesive adjuncts either before or after structure
formation.
[0046] FIG. 5 shows a perspective view of an alternative embodiment
wherein sheet 16 is provided in two or more layers which may
optionally be attached (e.g., laminated) together to create a
composite sheet material 51 wherein the two layers have different
properties. In a preferred embodiment, composite sheet material 51
includes a non-bioabsorbable layer 53 and a bioabsorbable layer 55.
In use, bioabsorbable layer 55 is placed in contact with the tissue
adjacent the defect. The non-bioabsorbable layer 53 is preferably
ePTFE and the bioabsorbable layer 55 is preferably a PGA:TMC
material in the form of a self-cohering web as taught by the Hayes
patents referred to above and incorporated herein by reference.
[0047] FIG. 5A shows a cross section of an alternative composite
sheet material 51 wherein the non-bioabsorbable layer 53 has
opposing surfaces 57 and 59 with different characteristics, for
example, surface 57 being rougher and/or more open than surface 59.
Rougher surface 57 is intended to encourage long term tissue
attachment and ingrowth while smoother surface 59 is intended as a
barrier to tissue attachment and ingrowth in order to prevent or
reduce the likelihood of tissue adhesions. If layer 53 is a porous
material, then smoother surface 59 may be provided with a suitably
small pore size while rougher surface 57 may be provided with a
suitably larger pore size. If desired, sheet 16 may be the result
of attaching two different layers together (as by bonding with an
adhesive or melt bonding, or by mechanical fastening means such as
sewing) to achieve the desired different surface characteristics.
Rougher surface 57 is preferably provided with a covering or
coating of bioabsorbable layer 55; when this layer 55 is
bioabsorbed after a suitable time, rougher surface 57 remains to
provide the desired long term tissue attachment. The presence of
the bioabsorbable layer 55 is anticipated to enhance healing as a
result of the increased inflammatory tissue response to the
bioabsorbable material. This may be desirable due to the chemically
inert character of the PTFE material (which consequently does
little to elicit a biological reaction from adjacent tissue when
implanted by itself.
[0048] It is also apparent that the bioabsorbable layer 55 may be
provided on one surface of an ePTFE material having similar
opposing surfaces, as well as providing such a bioabsorbable layer
on one surface of a differentially-sided ePTFE material.
[0049] A preferred material for the non-bioabsorbable layer 53 is
Gore-Tex Dual-Mesh.TM. with Corduroy.TM. surface (Flagstaff Ariz.);
this material has opposing surfaces with different tissue
attachment and ingrowth characteristics as described above.
[0050] FIG. 5B shows a cross-section of a sheet material 16 of the
present invention in the preferred form of a composite sheet
material 52 wherein non-bioabsorbable material 60 is placed within
bioabsorbable materials 62 and 63. FIG. 5C shows a cross-section of
a sheet material 16 of the present invention in the preferred form
of a composite sheet material 52 wherein non-bioabsorbable material
60 is placed between bioabsorbable materials 62 and 63. Either of
these composite sheet materials can serve as preferred base member
components of the present invention.
[0051] In both embodiments shown in FIGS. 5B and 5C,
non-bioabsorbable material 60 is preferably a porous, expanded,
polytetrafluoroethylene material (ePTFE). More preferably, the
ePTFE material has one or more holes traversing the thickness of
the material that are visible to the naked eye. The holes provide
for ingrowth of tissue and additional flexibility of the composite
sheet material. Most preferably, these "macroporous" ePTFE
materials have holes arranged in a pattern that imparts additional
flexibility to the composite sheet material while retaining
sufficient mechanical strength to support damaged or injured tissue
throughout the healing and rehabilitation process.
[0052] FIG. 6 is a longitudinal cross section of a band 18 that has
been flared using suitable tooling to create the bioabsorbable
layer 55 that may be adhered to a non-bioabsorbable layer 53 such
as ePTFE. This describes an alternative way to accomplish the
attachment of the plurality of hollow members to the sheet
component.
[0053] The following examples are provided for illustrative
purposes only as examples of particular embodiments of the
described invention. As such, they are not intended to be
limiting.
EXAMPLES
Example 1
[0054] This example describes the construction of a multiple tube
hernia repair device of the present invention as shown in FIG. 1. A
triblock copolymer of 67%/33% PGA:TMC (w/w) was acquired from US
Surgical (Norwalk Conn.) and formed into a self-cohering web as
generally taught by Hayes in U.S. Pat. No. 6,165,217. Sheets of
this copolymer web material were formed into the 3 component types
used in the construction of this device.
[0055] A first component used for making this device was a tube
formed from the self-cohering web sheets that had an area density
of approximately 8-10 mg/cm.sup.2 and a thickness of approximately
0.3 mm. The first step in making a tube was to cut an approximately
25 mm wide strip of the self-cohering web material from a piece of
"unset" web sheet perpendicular to the belt direction used in
forming the web. This strip of "unset" web material was then
wrapped lengthwise around an approximately 5 mm diameter stainless
steel rod into a "cigarette roll" having an exposed edge at the
surface of the resulting tube extending along the length of the
tube. This material then self-cohered (as generally taught by Hayes
in U.S. Pat. No. 6,165,217) at the overlapping portion of the
"cigarette roll" to form a 5 mm diameter tube that was
approximately 150 mm long. The strip of "unset" web material
wrapped around the stainless steel rod was then placed into a
Baxter Scientific Products (McGaw Park Ill.) constant temperature
oven, model DK-43, for approximately 30 minutes at 75.degree. C. to
"set" the web. The stainless steel rod and "set" web material were
then removed from the oven and allowed to cool. After cooling, the
tube formed from the now "set" web material was slipped off of the
stainless steel rod. Both ends of the "set" web tube were then
trimmed leaving a tube that was approximately 90 mm long. Each tube
was then placed onto a cutting die to create the notches 24 shown
in FIG. 1B. A piece of 0.05 mm thick Mylar.RTM. sheet (DuPont
Company, Wilmington Del.) was placed over the tube to protect it
from contamination. A lightweight plastic-faced mallet was then
used to lightly tap onto the tube through the Mylar.RTM. sheet to
cut out two notches 24 and centering hole 26 with the cutting die.
Multiple tubes were made using these methods.
[0056] Another component used in making this device was a
disc-shaped planar sheet of approximately 38 mm in diameter. This
disc-shaped planar sheet was made by first taking two 50 mm square
sheets of the "unset" self-cohering web material, each with an area
density of approximately 19 mg/cm.sup.2 and approximately 1 mm
thick. The two sheets were then stacked and placed in a restraining
frame fitted about the perimeter of the stacked sheets. The
restrained web material was then put into the Baxter Scientific
Products constant temperature oven for approximately 30 minutes at
75.degree. C. to bond the two pieces together to create a thicker
sheet and to "set" the web. After letting the web material cool to
room temperature, a disc was cut using an approximately 38 mm
diameter circular cutting die punch.
[0057] A third component used in making this device was a band
formed from an approximately 19 mm wide strip of copolymer web
material. This copolymer web strip had an area density of
approximately 6-8 mg/cm.sup.2 and a thickness of approximately 0.3
mm. This was made by rolling the strip of "unset" self-cohering web
material into a tube and then holding the overlapped ends together
to allow for self-cohering. The unset web material was then put
into a Baxter Scientific Products constant temperature oven for
approximately 30 minutes at 75.degree. C. The resulting band was
approximately 19 mm in diameter.
[0058] The device was then assembled by taking the disc first and
centering it on a centering pin extending from the center of the
surface of an assembly fixture. Then six of the tubes with notches
and centering holes were placed on top of the disc, also centering
them on the centering pin. The tubes were arranged so that they
were equally spaced radially. The assembly was then placed onto a
Branson model 8400 ultrasonic welder (Branson Sonic Power Co.,
Danbury Conn.). The ultrasonic welder had a Branson catenoidal
horn, model 609-010-020 and an approximately 7.6 mm diameter tip
that had an approximately 3.2 mm hole in the center to accommodate
the centering pin of the assembly fixture. The ultrasonic welder
also had a 1:0.6 booster. The downstop was set at approximately 0.4
mm with the downspeed set at number 4. Pressure was set at
approximately 0.08 MPa with the trigger set at number 2; time was
set to 0.2 seconds and the hold duration set at 1.0 seconds.
[0059] The ultrasonic welder was shut and activated 3 times for
each device. After ultrasonic welding, the six tubes were securely
attached to the disc-shaped sheet. The tubes were then folded up so
that they were oriented to be substantially perpendicular to the
sheet component. The band component was then placed around the
tubes to hold them in a bundled configuration wherein the tubes
were substantially parallel to each other along their lengths. Four
slits, spaced equally apart, were then cut into the disc
approximately three quarters of the way from the perimeter of the
disc to the center to facilitate insertion on the device into a
hernia defect site.
Example 2
[0060] This example describes the construction of a corrugated tube
hernia repair device of the present invention as shown in FIG. 4. A
triblock copolymer of 50% PGA:TMC (w/w) was made and formed into a
self-cohering web as generally taught by Hayes in U.S. Pat. No.
6,165,217. Sheets of this copolymer web material were formed into
some of the components used in the construction of this device.
Other components were made from expanded polytetrafluoroethylene
(ePTFE) and from a bioabsorbable polymer adhesive, as described
below.
[0061] A corrugated sheet was made by first placing a piece of the
"unset" PGA:TMC web sheet (approximately 100 mm square, about 0.2
mm thick having and having an area density of approximately 4-6
gm/cm.sup.2) onto a piece of PeCap.RTM. polyester screen, product
number 7-1000/45 (Sefar America, Monterey Park Calif.) material.
This screen material, by virtue of its surface texture, was used to
restrain the web material from dimensional change during the
"setting" process. A fixture approximately 125 mm square was then
placed onto the surface of the web sheet. The fixture was provided
with a set of multiple parallel rods with all of their centerlines
in the same plane, the rods being of approximately 2.4 mm diameter
and spaced 5.3 mm center-to-center. These rods acted as mandrels
for forming the hollow members of the corrugation.
[0062] A second piece of "unset" web material of the same type as
the first and of approximately the same dimensions was then placed
on top of the multiple parallel rod fixture. Unsecured rods of
approximately the same diameter as the rods in the fixture were
then placed on top of the second piece of "unset" web material,
between the parallel rods of the underlying fixture. These
unsecured rods were individually pushed down until they were in the
same plane as the parallel rods of the underlying fixture. The
result was that the second piece of "unset" web material now formed
the hollow members of the corrugated sheet as it assumed a
convoluted shape with self-cohering contact points on the bottom
piece of "unset" web material. Another piece of PeCap.RTM.
polyester screen was placed on top of the upper piece of "unset"
web material to restrain it from dimensional changes during the
"setting" process. An aluminum plate was placed on top of the
polyester and then a weight was placed on top of the entire
assembly.
The assembly was then placed into an oven at 80.degree. C. for 30
minutes to "set" the web material. After "setting" in the oven, the
web material was allowed to cool and then removed from the fixture
of multiple parallel rods.
[0063] Another component used in making this device was a sheet
component with a fillet and band for accepting a rolled up piece of
corrugated web material. The first step in making this sheet
component was to provide a piece of "unset" web sheet material
approximately 50 mm square. A circular cutting die was used to cut
an approximately 13 mm diameter hole in the center of it. A 19 mm
diameter aluminum rod, approximately 150 mm long, was then fixtured
to stand perpendicularly on a flat aluminum plate. The piece of
"unset" web material with a hole in its center was then pushed over
the aluminum rod. Since the hole in the "unset" web was smaller
than the diameter of the aluminum rod, and because the "unset" web
material was deformable, the difference in diameters between the
hole in the web material and the aluminum rod produced a flared
hole in the "unset" web. The aluminum rod and web material were
then placed into an oven at 80.degree. C. for 30 minutes to "set"
the web material. After allowing the web material to cool, it was
removed from the aluminum rod. The flared hole in the "set" web
material formed a combined fillet and band (as in FIG. 6) for
accepting the corrugated web material. The piece of "set" web
material with the flange was then adhered to a piece of ePTFE
material by using a bioabsorbable adhesive. The adhesive was made
from a mixture of poly(85% d,I-lactide-co-15% glycolide) (by mole;
abbreviated as 85% d,I-PLA:15% PGA) mixed 1:4 by weight in acetone.
It is apparent that this device could be made without the ePTFE
layer.
[0064] Barb components (FIG. 4, reference no. 42) were individually
formed by taking a piece of "unset" PGA:TMC web material
approximately 65 mm long.times.13 mm wide and wrapping this
lengthwise around a suitably tapered mandrel chosen to shape the
downwardly-angled barb. The strip of "unset" web material was
temporarily restrained to the mandrel by using a piece of PTFE pipe
tape. The tapered mandrel and restrained "unset" web material were
then put into an oven at approximately 80.degree. C. for
approximately 30 minutes to "set" the web material. After the web
material was "set" in the oven, it was removed from the mandrel.
Cutouts were then made to the center region of the now tapered band
to create flanges 44. The device was then assembled by taking the
corrugated sheet and rolling it into a tube. Some of the
bioabsorbable adhesive was applied to the circumference of one end
of this tube and also to the walls of the filleted band portion to
be attached to the sheet component. The end of the tube with
adhesive on it was then inserted in a perpendicular orientation
into the filleted band portion of the sheet component.
Bioabsorbable adhesive was then applied to the interiors of a pair
of anchoring barbs, after which they were immediately fitted over
the circumference of the plug component.
Example 3
[0065] This example describes a method used to alter the stiffness
and rate of bioabsorption of a bioabsorbable device. A solution was
made by mixing 65% d,I-PLA:35% PGA available from Birmingham
Polymers (Birmingham Ala.) in a 1:10 ratio by weight with acetone.
A device as described in Example 1 was dipped into this solution
which imbibed into the structure of the device, and then allowed to
air dry. The resulting coated device was stiffer than prior to
imbibing. Alternatively, this solution could be sprayed onto
devices to achieve similar effects. Other copolymer ratios can also
be used to vary the stiffness and rate of bioabsorption. Also,
other ratios of polymer:acetone can be used to vary the final
amount of polymer imbibed into or sprayed onto the structure of the
device.
Example 4
[0066] This example describes construction of a preferred
embodiment of the present invention having a base member in the
form of a composite sheet material having a non-bioabsorbable
component placed within a bioabsorbable component. This composite
base member can be used with any of the embodiments described
herein.
[0067] The composite sheet material for use as the base member of
the present invention was made in the form of a laminate of a
non-bioabsorbable ePTFE material and a bioasborbable PGA:TMC
self-cohering web material (67:33 weight percent) as taught by
Hayes (Ibid.). The ePTFE material made according to U.S. Pat. No.
5,858,505, which is incorporated herein by reference, was obtained
from W.L. Gore & Associates, Inc., Flagstaff, Ariz. under the
tradename GORE MYCROMESH.RTM. Biomaterial. In addition to having a
plethora of interconnected microscopic sized pores coursing
throughout the body of the ePTFE material, the material has holes
traversing the thickness of the material visible to the naked eye.
The starting materials for the bioabsorbable PGA:TMC component were
obtained as described above in Example 1.
[0068] The composite material was constructed by centering a
circular 7 cm diameter piece of ePTFE material between two 10
cm.times.10 cm sheets of PGA:TMC material. The PGA:TMC material was
in the form of an unset web having an area density between 20
mg/cm.sup.2 and 25 mg/cm.sup.2. The composite was overlaid on both
sides with a woven polyester web material (SEFAR AMERICA, INC,
SEFAR product number 7-1000/45 PeCap.RTM. polyester endless belt)
and placed in a restraining apparatus. Approximately five (5)
pounds of force was applied to the polyester web pieces with the
apparatus.
[0069] The restrained combination was placed in a constant
temperature oven at 100.degree. C. for ten (10) minutes in order to
set the bioabsorbable PGA:TMC web material and enclose the
non-bioabsorbable ePTFE material within the bioabsorbable material.
The composite material was allowed to cool to room temperature
before being removed from the restraining apparatus.
[0070] Excess bioabsorbable material was trimmed from the composite
sheet material to form a base member of the present invention. The
base member was attached to a plurality of substantially hollow
members as described in Example 1.
Example 5
[0071] This example describes construction of a preferred
embodiment of the present invention having a base member in the
form of a composite sheet material having a non-bioabsorbable
component placed between layers of bioabsorbable material. In this
example, the bioabsorbable self-cohering web had a volume percent
of 67:33, an area density of approximately 50 mg/cm.sup.2, and a
volume density of 0.35 g/cc. The ePTFE material was obtained from
W.L. Gore & Associates, Inc., Flagstaff, Ariz. under the
tradename GORE DUALMESH.RTM. Biomaterial. The ePTFE material is in
the form of a sheet having different textures on opposite sides of
the sheet material to elicit different tissue responses at an
implantation site.
[0072] In this example, the non-bioabsorbable ePTFE material was
placed between two layers of bioabsorbable PGA:TMC material,
restrained as described in Example 4, and ultrasonically welded
together.
[0073] The ultrasonic welder had a Branson circular high gain horn,
model 318 004 145 with an approximately 5 cm diameter tip having a
machined face honeycomb hole pattern. Each 6 mm hexagon machined
hole in the honeycomb pattern was spaced at 1 mm. The ultrasonic
welder also had a 1:2.5 booster. The downspeed was set at number 4.
Applied pressure was set at approximately 0.65 MPa with the trigger
set at number 2. The welding time was 0.8 seconds and assembly held
in place for a duration of 2.5 seconds.
[0074] Excess bioabsorbable material was trimmed from the composite
sheet material to form a base member of the present invention. The
base member was attached to a plurality of substantially hollow
members as described in Example 1.
[0075] While the principles of the invention have been made clear
in the illustrative embodiments set forth herein, it will be
obvious to those skilled in the art to make various modifications
to the structure, arrangement, proportion, elements, materials and
components used in the practice of the invention. To the extent
that these various modifications do not depart from the spirit and
scope of the appended claims, they are intended to be encompassed
therein.
* * * * *